This caution and condition is added to warn them that they should not receive the grace of God in vain, and to teach them that the grace of God doth not discharge man's obligation to his duty, nor excuse him for the neglect of it, and that conversion and sanctification, though it be God's work, yet it is man's duty.
Related Commentaries of Deuteronomy 30:10
Deuteronomy 30:10
10 If thou shalt hearken unto the voice of the LORD thy God, to keep his commandments and his statutes which are written in this book of the law, and if thou turn unto the LORD thy God with all thine heart, and with all thy soul.